Organic light emitting display device

ABSTRACT

An organic light emitting display device includes a substrate with a first emitting region adjacent a second emitting region, a first anode in the first emitting region, a first organic light emitting layer on the first anode, a second anode in the second emitting region, and a second organic light emitting layer on a part of the first anode and the second anode. The second organic light emitting layer includes a material different from the first organic light emitting layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/847,077,filed on Dec. 19, 2017, which is a continuation of application Ser. No.14/533,166, filed Nov. 5, 2014, now U.S. Pat. No. 9,876,186, whichclaims priority to and the benefit of Korean Patent Application No.10-2014-0069418, filed on Jun. 9, 2014, in the Korean IntellectualProperty Office, the entire contents of which each of which is herebyincorporated by reference.

BACKGROUND 1. Field

One or more embodiments described herein relate to an organic lightemitting display device.

2. Description of the Related Art

An organic light emitting display device includes organic layers betweenan anode and cathode. The organic layers include an emitting layer, ahole injecting layer, a hole transport layer, an electron transportlayer, and an electron injecting layer. In operation, electrons andholes generated by the anode and the cathode recombine in the emittinglayer to emit light.

In one type of organic light emitting display device, a plurality ofemitting layers are included to emit light of different colors. Forexample, a first emitting layer emits light of a first color, a secondemitting layer emits light of a second color, and a third emitting layeremits light of a third color. A particular color is emitted by combiningthe light of the first to third colors.

SUMMARY

In accordance with one embodiment, an organic light emitting displaydevice includes a substrate with a first emitting region adjacent asecond emitting region; a first anode in the first emitting region; afirst organic light emitting layer on the first anode; a second anode inthe second emitting region; and a second organic light emitting layer ona part of the first anode and the second anode, the second organic lightemitting layer including a material different from the first organiclight emitting layer.

A part of the second organic light emitting layer may be on an edgeportion of the first anode that faces the second anode. The secondorganic light emitting layer may extend from an upper portion of thesecond anode to an upper edge portion of the first anode that faces thesecond anode. The first organic light emitting layer may not overlap thesecond organic light emitting layer.

The first organic light emitting layer may emit red light, and thesecond organic light emitting layer may emit green or blue light. Thefirst organic light emitting layer may be in direct contact with thesecond organic light emitting layer on the first anode.

The substrate may include a third emitting region positioned on anotherside of the first emitting region, and the organic light emittingdisplay device may include a third anode on the third emitting region,and a third organic light emitting layer on the another part of thefirst anode and the third anode, the third organic light emitting layerincluding a material different from the first organic light emittinglayer and the second organic light emitting layer.

The third organic light emitting layer may be on an edge portion of thefirst anode that faces the third anode. The third organic light emittinglayer may extend from an upper portion of the third anode to an upperedge portion of the first anode that faces the third anode. The firstorganic light emitting layer may not overlap the second organic lightemitting layer and the third organic light emitting layer. The firstorganic light emitting layer may be in direct contact with the secondorganic light emitting layer and the third organic light emitting layeron the first anode.

The device may include a cathode over an entire surface of the substrateand facing the first anode and the second anode, wherein the firstorganic light emitting layer and the second organic light emitting layerare between the cathode and the first and second anodes.

In accordance with another embodiment, an organic light emitting displaydevice includes a substrate with a first emitting region adjacent asecond emitting region; a first anode in the first emitting region; afirst organic light emitting layer on the first anode and including afirst emitting material to emit a first color; a second organic lightemitting layer on the first organic light emitting layer and including asecond emitting material to emit light of a second color different fromthe first color; a second anode in the second emitting region; and athird organic light emitting layer on the second anode and including thesecond emitting material. The first color may be red and the secondcolor may be green or blue.

The second organic light emitting layer may include a third emittingmaterial to emit light of a third color different from the first colorand the second color, the substrate includes a third emitting region onanother side of the first emitting region, and the organic lightemitting display device includes: a third anode in the third emittingregion; and a fourth organic light emitting layer on the third anode andincluding the third emitting material.

The device may include a cathode over an entire surface of the substrateand facing the first anode and the second anode, wherein the firstorganic light emitting layer and the second organic light emitting layerare between the cathode and the first and second anodes.

In accordance with another embodiment, an organic light emitting displaydevice includes a substrate with a first emitting region adjacent asecond emitting region; a first anode in the first emitting region; afirst organic light emitting layer on the first anode and including afirst material to emit light of a first color and a second material toemit light of a second color; a second anode in the second emittingregion; and a second organic light emitting layer on the second anodeand including the second emitting material. The first color may be redand the second color may be green or blue.

The first organic light emitting layer may include a third emittingmaterial to emit light of a third color different from the first colorand the second color, the substrate may include a third emitting regionon another side of the first emitting region, and the organic lightemitting display device may include a third anode in the third emittingregion; and a fourth organic light emitting layer on the third anode andincluding the third emitting material. The device may include a cathodeover an entire surface of the substrate and facing the first anode andthe second anode, wherein the first organic light emitting layer and thesecond organic light emitting layer are between the cathode and thefirst and second anodes.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIG. 1 illustrates an embodiment of an organic light emitting displaydevice;

FIG. 2 illustrates a view along section line II-II′ in FIG. 1;

FIG. 3 illustrates an example of a color coordinate system for colorcorrection;

FIG. 4 illustrates an example of a color coordinate system includingportion IV in FIG. 3;

FIG. 5 illustrates an example of a color coordinate system with a sidevisibility improvement effect;

FIG. 6 illustrates an example of color shift curves;

FIG. 7 illustrates another embodiment of an organic light emittingdisplay;

FIG. 8 illustrates a view along section line VIII-VIII′ in FIG. 7;

FIG. 9 illustrates another example of a color coordinate system forcolor correction;

FIG. 10 illustrates another embodiment of an organic light emittingdisplay;

FIG. 11 illustrates a view along section line XI-XI′ in FIG. 10; and

FIGS. 12 and 13 illustrate another embodiment of an organic lightemitting display device.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Like reference numerals refer to like elements throughout.

FIG. 1 illustrates an embodiment of an organic light emitting displaydevice 100, and FIG. 2 is a cross-sectional view taken along line II-II′in FIG. 1. Referring to FIGS. 1 and 2, the organic light emittingdisplay device 100 includes a substrate 110, a plurality of anodes 120a, 120 b, and 120 c, a pixel defining layer 130, a hole transfer layer140, a plurality of organic light emitting layers 150 a, 150 b, and 150c, a plurality of auxiliary layers 150 a′ and 150 c′, an electrontransfer layer 160, and a cathode 170.

The substrate 110 may be or include an insulating substrate. Theinsulating substrate may be formed of a transparent glass materialhaving, for example, transparent SiO₂ as a main component. In oneembodiment, the insulating substrate may be made of an opaque materialor a plastic material. Further, the insulating substrate may be aflexible substrate that may bend, fold, or be rolled.

The substrate 110 may further include other structures formed on theinsulating substrate. Examples include but are not limited to wiring andan insulating layer. If the organic light emitting display device 100 isan active organic light emitting display device, the substrate 110 mayinclude a plurality of thin film transistors on the insulatingsubstrate. Each thin film transistor may include a gate electrode, asource electrode, a drain electrode, and a semiconductor layer includinga channel region. The semiconductor layer may be formed, for example, ofamorphous silicon, microcrystalline silicon, polycrystalline silicon,monocrystalline silicon, or oxide semiconductor. The drain electrodes ofone or more of the thin film transistors may be electrically connectedto the anodes 120 a, 120 b, and 120 c.

The substrate 110 may include a plurality of emitting regions E1, E2,and E3, and a non-emitting region NE. The emitting regions E1, E2, andE3 emit light. The non-emitting region NE do not emit light. Further,the emitting regions E1, E2, and E3 include the anodes 120 a, 120 b, and120, which are exposed by the pixel defining layer 130. The non-emittingregion NE includes the pixel defining layer 130. The emitting regionsE1, E2, and E3 may be formed to be spaced from each other. Thenon-emitting region NE may surround the emitting regions E1, E2, and E3.Further, the emitting regions E1, E2, and E3 may emit light havingdifferent colors.

The emitting regions E1, E2, and E3 include the first emitting regionE1, the second emitting region E2, and the third emitting region E3. Thefirst emitting region E1, the second emitting region E2, and the thirdemitting region E3 may correspond to a first pixel (or sub-pixel), asecond pixel (or sub-pixel), and a third pixel (or sub-pixel),respectively. The sub-pixels may be included in a same pixel.

The first emitting region E1, the second emitting region E2, and thethird emitting region E3 may emit a first, second, and third colorlight. The first, second, and the third color may be red, blue, andgreen, respectively. In another embodiment, one or more different coloror white light may be emitted.

In this embodiment, the first emitting region E1 is between the secondand third emitting regions E2 and E3. That is, the second and thirdemitting regions E2 and E3 are adjacent respective sides of the firstemitting region E1. In the embodiment of FIG. 2, the second emittingregion E2 is left of the first emitting region E1, and the thirdemitting region E3 is right of the first emitting region E1.

The anodes 120 a, 120 b, and 120 c are on the substrate 110 and arespaced from each other. For example, the anodes 120 a, 120 b, and 120 cmay be positioned in respective ones of the emitting regions E1, E2, andE3. That is, the anodes 120 a, 120 b, and 120 c are formed to bemutually separated from each other by pixels (or sub-pixels). The anodes120 a and 120 b, and 120 c may be independently driven, and may functionto transfer holes to the hole transfer layer 140 and respective ones ofthe organic light emitting layers 150 a, 150 b, and 150 c.

The anodes 120 a, 120 b, and 120 c may be made of a conductive materialhaving, for example, a high work function. If the organic light emittingdisplay device 110 is a bottom emission-type display device, the anodes120 a, 120 b, and 120 c may be formed of a material including but notlimited to ITO, IZO, ZnO, or In₂O₃, or a laminated layer thereof. If theorganic light emitting display device 100 is a top emission-type displaydevice, the anodes 120 a, 120 b, and 120 c may further include areflective layer, which is formed, for example, of Ag, Mg, Al, Pt, Pd,Au, Ni, Nd, Ir, Cr, Li, or Ca.

The anodes 120 a, 120 b, and 120 c may be modified in various ways, forexample, to have a structure of two or more layers using two or moredifferent materials. The anodes 120 a, 120 b, and 120 c may be formed,for example, through a sputtering process using a fine metal mask (FMM).

The anodes 120 a, 120 b, and 120 c include the first anode 120 a, thesecond anode 120 b, and the third anode 120 c. The first anode 120 a,the second anode 120 b, and the third anode 120 c may be respectivelypositioned in the first emitting region E1, the second emitting regionE2, and the third emitting region E3. The first anode 120 a, the secondanode 120 b, and the third anode 120 c may be made of the same materialor may be made of different materials.

The pixel defining layer 130 is on the substrate 110 and the anodes 120a, 120 b, and 120 c. The pixel defining layer 130 exposes at least aportion of the anodes 120 a, 120 b, and 120 c. For example, regionswhere the pixel defining layer 130 is not positioned may correspond tothe emitting regions E1, E2, and E3. A region where the pixel defininglayer 130 is positioned may correspond to the non-emitting regions NE.

The pixel defining layer 130 may be made of an insulating material. Inone embodiment, the pixel defining layer 130 may be made of at least oneorganic material selected from the group including benzo cyclo butene(BCB), polyimide (PI), poly amide (PA), acrylic resin, and phenol resin,or may be made of an inorganic material such as silicon nitride.

The hole transfer layer 140 may be positioned on the anodes 120 a, 120b, and 120 c and the pixel defining layer 130. In one embodiment, thehole transfer layer 140 may be commonly formed over the entire surfaceof the substrate 110. The hole transfer layer 140 may be formed, forexample, by a deposition process using an open mask. The hole transferlayer 140 may be selectively formed only on the emitting regions E1, E2,and E3. The hole transfer layer 140 may function to transfer holes fromthe anode to the organic light emitting layers 150 a, 150 b, and 150 c.

The hole transfer layer 140 may include at least one of a hole injectinglayer or a hole transport layer. The hole injecting layer may be indirect contact with at least one of the anodes 120 a, 120 b, and 120 c,and the hole transport layer may be in direct contact with at least oneof the organic light emitting layers 150 a, 150 b, and 150 c.

The hole injecting layer may include a hole injecting material, e.g.,phthalocyanine compounds including but not limited to copperphthalocyanine, TCTA or m-MTDATA of starburst-type amine derivatives,Pani/DBSA (Polyaniline/Dodecylbenzenesulfonic acid) or PEDOT/PSS(poly(3,4-ethylenedioxythiophene)/Poly(4-styrenesulfonate) that isconducting polymer, Pani/CSA(Polyaniline/Camphor sulfonic acid), orPANI/PSS(Polyaniline)/Poly (4-styrene-sulfonate).

The hole transport layer may include a hole transport material, e.g.,1,3,5-tricarbazolylbenzene, 4,4′-biscarbazolylbiphenyl,polyvinylcarbazol, m-biscarbazolylphenyl,4,4′-biscarbazolyl-2,2′-dimethylbiphenyl, 4,4′,4″-tri(N-carbazolyl)triphenylamine, 1,3,5-tri (2-carbazolylphenyl)benzene, 1,3,5-tris(2-carbazolyl-5-methoxphenyl) benzene, bis(4-carbazolylphenyl)silane,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′ diamine(TDP), N,N′-di(naphthalene-1-il)-N,N′-diphenyl benzidine (NPD),N,N′-dephenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB),poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), or(poly(9,9-dioctylfluorene-co-bis-(4-butylphenyl-bis-N,N-phenyl-1,4-phenylenediamin)(PFB), but is not limited thereto.

The organic light emitting layers 150 a, 150 b, and 150 c are on thehole transfer layer 140. The organic light emitting layers 150 a, 150 b,and 150 c emit light of specific colors. For example, in the pluralityof organic light emitting layers 150 a, 150 b, and 150 c, holes andelectrons provided from anodes 120 a, 120 b, and 120 c and the cathode170 recombine to form excitons. As the energy level of the excitonschanges, light of specific colors (e.g., red, green, blue, yellow,white, etc.) are emitted.

The organic light emitting layers 150 a, 150 b, and 150 c include thefirst organic light emitting layer 150 a, the second organic lightemitting layer 150 b, and the third organic light emitting layer 150 c.The first organic light emitting layer 150 a, the second organic lightemitting layer 150 b, and the third organic light emitting layer 150 cmay be made of different materials. The first organic light emittinglayer 150 a may include a first emitting material that emits afirst-color light, the second organic light emitting layer 150 b mayinclude a second emitting material that emits a second-color light thatis different from the first color, and the third organic light emittinglayer 150 c may include a third emitting material that emits athird-color light that is different from the first color and the secondcolor.

The first color, the second color, and the third color may be, forexample, red, blue, and green respectively, or a different combinationof colors including white. For example, the first organic light emittinglayer 150 a, the second organic light emitting layer 150 b, and thethird organic light emitting layer 150 c may emit red light, blue light,and green light, respectively.

If the first organic light emitting layer 150 a emits red light, thefirst organic light emitting layer 150 a may be made of a high-molecularmaterial, a low-molecular material, or a high/low-molecular mixedmaterial which inherently emits red light. In one embodiment, the redorganic light emitting layer may include a red host material and a reddopant material. The red host material may be, for example, at least oneselected from the group including{Bis(2-(2-hydroxyphenyl)benzothiazolato) zinc (Zn(BTZ)2)} and{Bis-(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminium}, but isnot limited thereto. The red dopant material may include, for example,PtOEP, Ir(piq)₃, Btp₂Ir(acac) or DCJTB.

If the second organic light emitting layer 150 b emits blue light, thesecond organic light emitting layer 150 b may be made of ahigh-molecular material, a low-molecular material, or ahigh/low-molecular mixed material which inherently emits blue light. Inone embodiment, the blue organic light emitting layer may include a bluehost material and a blue dopant material. The blue host material may be,for example, at least one selected from the group including anthracenederivatives and carbazole-based compound. The anthracene derivatives maybe, for example, 9,10-(2-dinaphtyl)anthracene (AND). The carbazole-basedcompound may be, for example, 4,4′-(carbazole-9-il) biphenyl (CBP). Theblue dopant material may include, for example, F₂Irpic, (F₂ppy)₂Ir(tmd),Ir(dfppz)₃, or ter-fluorene.

If the third organic light emitting layer 150 c emits green light, thethird organic light emitting layer 150 c may be made of a high-molecularmaterial, a low-molecular material, or a high/low-molecular mixedmaterial which inherently emits green light. In one embodiment, thegreen organic light emitting layer may include a green host material anda green dopant material. The green host material may be, for example, atleast one selected from the group including anthracene derivatives andcarbazole-based compound. The anthracene derivatives may be, forexample, 9,10-(2-dinaphtyl)anthracene (AND). The carbazole-basedcompound may be, for example, 4,4′-(carbazole-9-il) biphenyl (CBP). Thegreen dopant material may include, for example, Ir(ppy)₃(ppy=phenylpyridine), Ir(ppy)₂(acac), Ir(mpyp)₃, or C545T.

The first organic light emitting layer 150 a may be positioned on thefirst anode 120 a in the first emitting region E1. In one embodiment,the first organic light emitting layer 150 a may be positioned on theremaining region except for part of the first anode 120 a in the firstemitting region E1. For example, the first organic light emitting layer150 a may be positioned on an edge portion 20 of the first anode 120 athat faces the second anode 120 b, for example, on the remaining regionexcept for the left edge portion. The first organic light emitting layer150 a may be positioned on the whole surface of the first anode 120 a inthe first emitting region E1.

The second organic light emitting layer 150 b may be positioned on partof the first anode 120 a in the first emitting region E1 and in thesecond emitting region E2. In one embodiment, the second organic lightemitting layer 150 b may be on the whole surface of the second anode 120b in the second emitting region E2. Further, the second organic lightemitting layer 150 b may be not only in the second emitting region E2,but also part of the first emitting region E1.

The part of the first emitting region E1 may correspond to an edgeportion of the first anode 120 a that faces the second anode 120 b, forexample, the left edge portion. In this case, the second organic lightemitting layer 150 b may be formed to extend from the upper portion ofthe second anode 120 b to the upper portion of the edge portion 20 ofthe first anode 120 a that faces the second anode 120 b. For example,the second organic light emitting layer 150 b may completely cover thepixel defining layer 130 that is between the first anode 120 a and thesecond anode 120 b.

The first organic light emitting layer 150 a and the second organiclight emitting layer 150 b may not overlap each other. For example, thesecond organic light emitting layer 150 b may be on part of the firstanode 120 a that is positioned in the first emitting region E1 and maybe in the region except for the part of the first anode 120 a. The firstorganic light emitting layer 150 a and the second organic light emittinglayer 150 b may overlap each other in the first emitting region E1.

The first organic light emitting layer 150 a may be in direct contactwith the second organic light emitting layer 150 b on the first anode120 a, that is positioned in the first emitting region E1. In oneembodiment, the side surface of the first organic light emitting layer150 a may be in direct contact with the second organic light emittinglayer 150 b.

The third organic light emitting layer 150 c may be on the third anode120 c that is positioned in the third emitting region E3. In oneembodiment, the third organic light emitting layer 150 c may be on thewhole surface of the third anode 120 c that is positioned in the thirdemitting region E3.

Although the first organic light emitting layer 150 a is positioned onmost of the region of the first anode 120 a in the first emitting regionE1, the second organic light emitting layer 150 b may be on a partialregion of the first anode 120 a in the first emitting region E1. On theother hand, the second organic light emitting layer 150 b may be on thewhole surface of the second anode 120 b in the second emitting regionE2. The third organic light emitting layer 150 c may be on the wholesurface of the third anode 120 c in the third emitting region E3.

The auxiliary layers 150 a′ and 150 c′ may be between at least a part ofthe organic light emitting layers 150 a, 150 b, and 150 c and the holetransfer layer 140. The auxiliary layers 150 a′ and 150 c′ may functionto adjust a resonance distance in each pixel (or sub-pixel). Forexample, the auxiliary layers 150 a 1 and 150 c′ may function toheighten the color purity and light emitting efficiency of light emittedfrom the organic light emitting layers 150 a, 150 b, and 150 c. Theauxiliary layers 150 a′ and 150 c′ may include the first auxiliary layer150 a′ and the second auxiliary layer 150 c′.

The first auxiliary layer 150 a′ may be between the first organic lightemitting layer 150 a and the hole transfer layer 140. The firstauxiliary layer 150 a′ may completely overlap the first organic lightemitting layer 150 a. In one embodiment, the first auxiliary layer 150a′ may be successively formed together with the first organic lightemitting layer 150 a in the same chamber. The first auxiliary layer 150a′ may function to adjust the resonance distance of the first-colorlight emitted from the first organic light emitting layer 150 a. Forexample, the first auxiliary layer 150 a′ may adjust the distancebetween the first anode 120 a and the cathode 170 in the first emittingregion E1. In one embodiment, the first auxiliary layer 150 a′ mayinclude, for example, at least one selected from the group includingsilicon nitride (SiN_(X)), silicon oxide (SiO₂), and silicon oxynitride(SiO_(N)).

The second auxiliary layer 150 c′ may be between the third organic lightemitting layer 150 c and the hole transfer layer 140. The secondauxiliary layer 150 c′ may completely overlap the third organic lightemitting layer 150 c. In one embodiment, the second auxiliary layer 150c′ may be successively formed together with the third organic lightemitting layer 150 c in the same chamber. The second auxiliary layer 150c′ may function to adjust the resonance distance of the third-colorlight emitted from the third organic light emitting layer 150 c. Forexample, the second auxiliary layer 150 c′ may adjust the distancebetween the third anode 120 c and the cathode 170 in the third emittingregion E3.

The thickness of the second auxiliary layer 150 c′ may be different from(e.g., thinner than) the thickness of the first auxiliary layer 150 a′.Further, the second auxiliary layer 150 c′ may be made of the same or adifferent material as the material of the first auxiliary layer 150 a′.The second auxiliary layer 150 c′ may include, for example, at least oneselected from the group including silicon nitride (SiN_(X)), siliconoxide (SiO₂), and silicon oxynitride (SiO_(N)).

The electron transfer layer 160 may be positioned on the organic lightemitting layers 150 a, 150 b, and 150 c and the pixel defining layer130. In one embodiment, the electron transfer layer 160 may be commonlyformed on the whole surface of the substrate 110. The electron transferlayer 160 may be formed, for example, by a deposition process using anopen mask. In one embodiment, the electron transfer layer 160 may beselectively formed only on the emitting regions E1, E2, and E3. Theelectron transfer layer 160 may function to transfer electrons from thecathode 170 to the organic light emitting layers 150 a, 150 b, and 150c.

The electron transfer layer 160 may include at least one of an electroninjecting layer or an electron transport layer. The electron injectinglayer may be in direct contact with the cathode 170. The electrontransport layer may be in direct contact with the organic light emittinglayers 150 a, 150 b, and 150 c.

The electron injecting layer may include an electron injecting material.The electron injecting material may include, for example, at least oneof LiF, LiQ, or NaQ. As another example, the electron injecting materialmay include NaCl, CsF, Li₂O, or BaO.

The electron transport layer may include an electron transport material.The electron transport material may include, for example, at least oneof a pyrene series material, a triazine series material, or ananthracene series material. As another example, the electron transportmaterial may include materials such as but not limited to quinolinederivatives, and particularly, tris(8-quinolinolate)aluminum (Alq3),TAZ, and Balq.

The cathode 170 may be positioned on the electron transfer layer 160. Inone embodiment, the cathode 170 may be commonly formed on the wholesurface of the substrate 110. The cathode 170 may be formed, forexample, by a deposition process using an open mask. In one embodiment,the cathode 170 may be selectively formed only on the emitting regionsE1, E2, and E3. The cathode 170 may function to provide electrons to theorganic light emitting layers 150 a, 150 b, and 150 c.

FIGS. 3 and 4 illustrate an example of color correction effects of theorganic light emitting display device 100. More specifically, FIG. 3illustrates an embodiment of a color coordinate system explaining colorcorrection effects of an organic light emitting display device, which,for example, may correspond to device 100 in FIG. 1. FIG. 4 illustratesan example of a color coordinate system with portion IV in FIG. 3enlarged. Moreover, FIGS. 3 and 4 illustrate the color coordinates asseen from a front perspective of the organic light emitting displaydevice 100.

First, referring to FIG. 3, in a CIE color coordinate system: Rcorresponds to the color coordinates of light of a first color (e.g.,red) emitted from the first organic light emitting layer 150 a; Bcorresponds to the color coordinates of light of a second color (e.g.,blue) emitted from the second organic light emitting layer 150 b; and Ccorresponds to the color coordinates of light of a third color (e.g.,green) emitted from the third organic light emitting layer 150 c. The R,G, and B color coordinates form a standard triangle (ST).

If only the first organic light emitting layer 150 a is positioned onthe first emitting region E1, only the second organic light emittinglayer 150 b is positioned on the second emitting region E2, and only thethird organic light emitting layer 150 c is positioned on the thirdemitting region E3, the organic light emitting display device 100 emitslight having color coordinates in the standard triangle ST.

If the first organic light emitting layer 150 a is unable to emithigh-purity red light (e.g., if the y color coordinates of light emittedfrom the first organic light emitting layer 150 a are larger than the ycolor coordinates of high-purity red light), the organic light emittingdisplay device 100 may not properly express high-purity red color. Inthis case, color correction may be performed so that the organic lightemitting display device 100 expresses high-purity red color. Asillustrated in FIGS. 1 and 2, color correction may be performed byarranging not only the first organic light emitting layer 150 a thatemits the red light, but also the second organic light emitting layer150 b that emits the blue light.

Referring to FIGS. 3 and 4, as the ratio of the area of the secondorganic light emitting layer 150 b to the area of the first organiclight emitting layer 150 a in the first emitting region E1 increases,the color coordinates R may move in the direction of an arrow on oneside of the standard triangle ST. In one embodiment, the colorcoordinates of light emitted from the first emitting region E1 of theorganic light emitting display device 100 of FIG. 1 may be set to R′.

For example, through proper adjustment of the area of the second organiclight emitting layer 150 b in the first emitting region E1, they colorcoordinates of the color coordinates R′ of light emitted from the firstemitting region E1 may equally match the y color coordinates of the redcolor coordinates of the sRGB color coordinate system. In this case,high-purity red light may be emitted from the first emitting region E1.In this case, R′, B, and G form a changed triangle CH, and the organiclight emitting display device 100 of FIG. 1 may emit light having thecolor coordinates in the changed triangle CH.

FIGS. 5 and 6 illustrate an example of side visibility improvementeffects of the organic light emitting display device 100 according toone embodiment. FIG. 5 illustrates an example of a color coordinatesystem explaining a side visibility improvement effect of the organiclight emitting display device 100. FIG. 6 is a graph in which line A-A′and line B-B′ of the color coordinate system are converted to colorshift curves according to their angles.

First, referring to FIG. 5, A indicates the color coordinates when lightemitted from the first emitting region E1 is seen from a front surfaceof the organic light emitting display device 100 (e.g., the direction ofa normal line of the display surface of the organic light emittingdisplay device 100) in the case where only the first organic lightemitting layer 150 a is positioned on the first emitting region E1. A′indicates color coordinates when light emitted from the first emittingregion E1 is seen from a side surface of the organic light emittingdisplay device 100 (e.g., the direction that is oriented 60 degrees fromthe normal line of the display surface of the organic light emittingdisplay device 100) in the case where only the first organic lightemitting layer 150 a is positioned on the first emitting region E1. Asdescribed above, if the organic light emitting display device 100 isseen as moving from the front surface to the side surface of the organiclight emitting display device 100, the color coordinates of the redlight, and in particular, the y color coordinates, may abruptly changein the direction of the arrow.

B indicates color coordinates when light emitted from the first emittingregion E1 is seen from the front surface of the organic light emittingdisplay device 100 (e.g., the direction of the normal line of thedisplay surface of the organic light emitting display device 100) in thecase where not only the first organic light emitting layer 150 a, butalso the second organic light emitting layer 150 b, is positioned on thefirst emitting region E1. B′ indicates color coordinates when lightemitted from the first emitting region E1 is seen from the side surfaceof the organic light emitting display device 100 (e.g., the directionoriented 60 degrees from the normal line of the display surface of theorganic light emitting display device 100) in the case where not onlythe first organic light emitting layer 150 a, but also the secondorganic emitting layer 150 b, is positioned on the first emitting regionE1.

As described above, if the organic light emitting display device 100 isseen as moving from the front surface to the side surface of the organiclight emitting display device 100, the color coordinates of the redlight may change in the direction of the arrow, but the variation of they color coordinates is not relatively large. A main factor thatinfluences visibility is the y color coordinates. If two lights arecombined in the first emitting region E1 to form mixed light, the sidevisibility of the mixed light becomes higher than the side visibility ofnon-mixed light.

Referring to FIG. 6, curve X corresponds to line A-A′ in FIG. 5 forconversion of a color shift curve according to the angle thereof. CurveY corresponds to line B-B′ in FIG. 5 for conversion to a color shiftcurve according to the angle thereof. As illustrated in FIG. 6, as theangle at which the organic light emitting display device 100 is seenincreases, curve Y (e.g., the color shift of the mixed light) decreasesand becomes smaller than the color shift of the non-mixed light. Thus,by arranging not only the first organic light emitting layer 150 a, butalso the second organic light emitting layer 150 b, in the firstemitting region E1, the visibility of red light is improved.

FIG. 7 illustrates another embodiment of an organic light emittingdisplay 101, and FIG. 8 is a cross-sectional view taken along lineVIII-VIII′ in FIG. 7. Referring to FIGS. 7 and 8, a first organic lightemitting layer 151 a, a second organic light emitting layer 151 b, athird organic light emitting layer 151 c, a first auxiliary layer 151a′, and a second auxiliary layer 151 c′ may be made of the samematerials as the first organic light emitting layer 150 a, the secondorganic light emitting layer 150 b, the third organic light emittinglayer 150 c, the first auxiliary layer 150 a′, and the second auxiliarylayer 150 c′, respectively.

However, the first organic light emitting layer 151 a may be positionedon a remaining area except for part of the first anode 120 a on thefirst emitting layer. The second organic light emitting layer 151 b maybe positioned on an entire surface of the second anode 120 b on thesecond emitting region E2, and the third organic light emitting layer151 c may be positioned on part of the first anode 120 a on the firstemitting region E1 and on the entire surface of the third anode 120 c onthe third light emitting region E3.

Here, the part of the first emitting region E1 may correspond to an edgeportion of the first anode 120 a that faces the third anode 120 c, e.g.,the right edge portion. In this case, the third organic light emittinglayer 151 c may extend from the upper portion of the third anode 120 cto the upper edge portion of the first anode 120 a that faces the thirdanode 120 c. Further, the first auxiliary layer 151 a′ may completelyoverlap the third organic light emitting layer 151 c, and may be formedon the lower portion of the third organic light emitting layer 151 c.

FIG. 9 illustrates an example of a color coordinate system explainingcolor correction effects of the organic light emitting display device inFIG. 7. Referring to FIG. 9, as a ratio of the area of the third organiclight emitting layer 151 c to the area of the first organic lightemitting layer 151 a in the first emitting region E1 increases, thecolor coordinates R may move in the direction of an arrow along one sideof the standard triangle ST. In one embodiment, the color coordinates oflight emitted from the first emitting region E1 of the organic lightemitting display device 101 in FIG. 7 may be R″. In this case, R″, B,and G form a changed triangle CH′, and the organic light emittingdisplay device 101 in FIG. 7 may emit the light having color coordinatesin the changed triangle CH′.

FIG. 10 illustrates another embodiment of an organic light emittingdisplay device 102, and FIG. 11 is a view taken along section lineXI-XI′ in FIG. 10. Referring to FIGS. 10 and 11, a first organic lightemitting layer 152 a, a second organic light emitting layer 152 b, athird organic light emitting layer 152 c, a first auxiliary layer 152a′, and a second auxiliary layer 152 c′ may be made of the samematerials as the first organic light emitting layer 150 a, the secondorganic light emitting layer 150 b, the third organic light emittinglayer 150 c, the first auxiliary layer 150 a′, and the second auxiliarylayer 150 c′, respectively.

However, the first organic light emitting layer 152 a may be positionedon the center portion of the first anode 120 a positioned on the firstemitting layer. The second organic light emitting layer 152 b may bepositioned on part of the first anode 120 a on the first emitting regionE1 and on the entire surface of the second anode 120 b on the secondemitting region E2. The third organic light emitting layer 152 c may bepositioned on another part of the first anode 120 a on the firstemitting region E1 and on the entire surface of the third anode 120 c onthe third light emitting region E3.

Here, the part of the first emitting region E1 may correspond to an edgeportion of the first anode 120 a that faces the second anode 120 b,e.g., the left edge portion. The other part of the first light emittingregion E1 may correspond to an edge portion of the first anode 120 athat faces the third anode 120 c, e.g., the right edge portion. In thiscase, the second organic light emitting layer 152 b may extend from theupper portion of the second anode 120 b to the upper edge portion of thefirst anode 120 a that faces the second anode 120 b. The third organiclight emitting layer 152 c may extend from the upper portion of thethird anode 120 c to the upper edge portion of the first anode 120 athat faces the third anode 120 c.

Further, the first auxiliary layer 152 a′ may completely overlap thefirst organic light emitting layer 152 a, and may be formed on the lowerportion of the first organic light emitting layer 152 a. The secondauxiliary layer 152 a′ may completely overlap the third organic lightemitting layer 152 c, and may be formed on the lower portion of thethird organic light emitting layer 152 c. Further, the first organiclight emitting layer 152 a may not overlap the second organic lightemitting layer 152 b and the third organic light emitting layer 152 c.Further, the first organic light emitting layer 152 a may directlycontact the second organic light emitting layer 152 b and the thirdorganic light emitting layer 152 c on the first anode 120 a.

FIG. 12 illustrates another embodiment of an organic light emittingdisplay device 103. Referring to FIG. 12, the first organic lightemitting layer 153 a may be made of the same material as the firstorganic light emitting layer 150 a as described above. For example, thefirst organic light emitting layer 153 a includes a first emittingmaterial that emits light of a first color, e.g., red. The first organiclight emitting layer 153 a may be positioned on the entire surface ofthe first anode 120 a on the first emitting region E1.

A second organic light emitting layer 153 b may be positioned on thefirst organic light emitting layer 153 a. The second organic lightemitting layer 153 b may include a second light emitting material thatemits light of a second color (e.g., blue), and/or a third organic lightemitting material that emits light of a third color, e.g., green.

An intermediate layer 180 may be between the first organic lightemitting layer 153 a and the second organic light emitting layer 153 b.The intermediate layer 180 may include a charge generating layer 180 cbetween a sub-electron transfer layer 180 a, a sub-hole transfer layer180 b. The sub-electron transfer layer 180 a is adjacent to the firstorganic light emitting layer 153 a, and may be made of the same materialas the electron transfer layer 160. The sub-hole transfer layer 180 b isadjacent to the second organic layer 153 b, and is made of the samematerial as the hole transfer layer 140. The charge generating layer 180c generates electrons and holes.

The electrons generated from the charge generating layer 180 c may betransferred to the first organic light emitting layer 153 a through thesub-electron transfer layer 180 a. The holes generated from the chargegenerating layer 180 c may be transferred to the second organic lightemitting layer 153 b through the sub-hole transfer layer 180 b. Thecharge generating layer 180 c may prevent the electrons and holes frommoving in opposite directions.

In the organic light emitting display device 103 according to anotherembodiment, the first auxiliary layer 150 a′ may be omitted. In thiscase, the function of the first auxiliary layer 150 a′ as describedabove (i.e., the resonance distance adjustment function) may beperformed by the intermediate layer 180.

The third organic light emitting layer 153 c may be made of the samematerial as the second organic light emitting layer 153 b as describedabove. That is, the third organic light emitting layer 153 c may includea second light emitting material that emits light of the second color.The third organic light emitting layer 153 c may be on the entiresurface of the second anode 120 b on the second emitting region E2.

A fourth organic light emitting layer 153 d may be made of the samematerial as the third organic light emitting layer 153 c as describedabove. That is, the fourth organic light emitting layer 153 d mayinclude a third light emitting material that emits light of the thirdcolor. The fourth organic light emitting layer 153 d may be on theentire surface of the third anode 120 c on the third emitting region E3.

The second auxiliary layer 153 d′ may be made of the same material asthe second auxiliary layer 150 c′ as described above. The secondauxiliary layer 153 d′ may completely overlap the fourth organic lightemitting layer 153 d on the lower portion of the fourth organic lightemitting layer 153 d.

Because the first organic light emitting layer 153 a and the secondorganic light emitting layer 153 b overlap each other in the firstemitting region E1, the color of light emitted from the first emittingregion E1 may be corrected.

FIG. 13 is a cross-section view of another embodiment of an organiclight emitting display device 104. Referring to FIG. 13, the firstorganic light emitting layer 154 a may include a second emittingmaterial and/or a third emitting material in addition to the firstemitting material. For example, the first organic light emitting layer154 a may include a mixture of a plurality of emitting materials. Thefirst organic light emitting layer 154 a may be positioned on the entiresurface of the first anode 120 a in the first emitting region E1.

The first auxiliary layer 154 a′ may be made of the same material as thefirst auxiliary layer 150 a′ as described above. The first auxiliarylayer 154 a′ may be formed to completely overlap the first organic lightemitting layer on the lower portion of the first organic light emittinglayer.

The second organic light emitting layer 154 b may be made of the samematerial as the second organic light emitting layer 150 b as describedabove. For example, the second organic light emitting layer 154 b mayinclude a second light emitting material. The second organic lightemitting layer 154 b may be positioned on the entire surface of thesecond anode 120 b in the second emitting region E2.

The third organic light emitting layer 154 c may be made of the samematerial as the third organic light emitting layer 150 c as describedabove. For example, the third organic light emitting layer 154 c mayinclude a third light emitting material that emits the third-colorlight. The third organic light emitting layer 154 c may on the entiresurface of the third anode 120 c on the third emitting region E3.

The second auxiliary layer 154 c′ may be made of the same material asthe second auxiliary layer 150 c′ as described above. The secondauxiliary layer 154 c′ may be formed to completely overlap the thirdorganic light emitting layer 154 c on the lower portion of the thirdorganic light emitting layer 154 c.

As described above, because the first organic light emitting layer 154 aincludes the second emitting material and/or the third emitting materialin addition to the first emitting material, the color of light emittedfrom the first emitting region E1 may be corrected.

By way of summation and review, in one type of organic light emittingdisplay device, a plurality of emitting layers are included to emitlight of different colors. For example, a first emitting layer emitslight of a first color, a second emitting layer emits light of a secondcolor, and a third emitting layer emits light of a third color. Aparticular color is emitted by combining the light of the first to thirdcolors.

However, if at least any one of the first to third emitting layers doesnot properly emit light of a specific color, the color expression of theorganic light emitting display device may deteriorate. For example, ifthe first emitting layer in a red pixel emits low-purity red light(e.g., orange light) rather than high-purity red light, the organiclight emitting display device that includes the first emitting layer maynot properly display the red color.

Further, the low-purity red light emitted from the first emitting layermay have low side visibility. Accordingly, when a display surface of theorganic light emitting display device is seen from the side of theorganic light emitting display device, the purity of the red lightemitted from the first emitting layer may be further lowered.

In accordance with one or more of the aforementioned embodiments, anorganic light emitting display device is provided which has improvedcolor expression and side visibility.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of skill in the art as of thefiling of the present application, features, characteristics, and/orelements described in connection with a particular embodiment may beused singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwiseindicated. Accordingly, it will be understood by those of skill in theart that various changes in form and details may be made withoutdeparting from the spirit and scope of the present invention as setforth in the following claims.

What is claimed is:
 1. An organic light emitting display device,comprising: a substrate having a first emitting region adjacent to asecond emitting region; a first anode in the first emitting region; afirst organic light emitting layer on the first anode and including afirst emitting material to emit a first color; a second organic lightemitting layer on the first organic light emitting layer and including asecond emitting material to emit light of a second color different fromthe first color; a charge generation layer between the first organiclight emitting layer and the second organic light emitting layer; asecond anode in the second emitting region; and a third organic lightemitting layer on the second anode and including the second emittingmaterial.
 2. The device as claimed in claim 1, wherein the first coloris red and wherein the second color is green or blue.
 3. The device asclaimed in claim 1, wherein: the second organic light emitting layerincludes a third emitting material to emit light of a third colordifferent from the first color and the second color, the substrateincludes a third emitting region on another side of the first emittingregion, and the organic light emitting display device includes: a thirdanode in the third emitting region; and a fourth organic light emittinglayer on the third anode and including the third emitting material. 4.The device as claimed in claim 1, further comprising: a cathode over anentire surface of the substrate and facing the first anode and thesecond anode, wherein the first organic light emitting layer and thesecond organic light emitting layer are between the cathode and thefirst and second anodes.
 5. The device as claimed in claim 1, furthercomprising: a hole transfer layer between the second organic lightemitting layer and the charge generation layer; and an electron transferlayer between the first organic light emitting layer and the chargegeneration layer.